P206 Indicators of inadequate response to anti-tumour necrosis factor therapies in patients with ulcerative colitis from real-world practice settings

Background: The study objective was to determine the incidence of inadequate response to induction (I-phase) and maintenance (M-phase) treatment with anti-tumor necrosis factor therapies (anti-TNFs) in ulcerative colitis (UC) patients in real-world practice settings. Methods: A retrospective cohort study was performed using the US Clinformatics administrative health claims database (2005-2012). Patients with UC were identified as having the following: ≥2 claims for UC (ICD-9-556.xx); ≥1 claim for an anti-TNF [adalimumab (ADA) or infliximab (INF)]; ≥6 months of plan enrollment prior to the first diagnosis of UC (index date); and ≥1 year follow-up from the first anti-TNF (index drug). Non anti-TNF UC treatments included 5-ASA, oral or injectable corticosteroids, enteral budesonide, or immunomodulators. The indicators used as a proxy for assessing inadequate response during the Iphase were switching to another anti-TNF or augmentation with any new non anti-TNF treatment. Additional indicators of dose escalation, flares, UC-related surgery, and UCrelated urgent care (hospitalization or emergency room visit) were included in the M-phase. Patients who received labeled doses of anti-TNFs without any encounters of UC-related urgent care (during the I-phase) and with ≥2 claims for anti-TNF were included in the Mphase. Bivariate statistical analyses were performed using chi-square test. Median time to and rates of inadequate response were estimated using the Kaplan-Meier Method. Results: A total of 587 UC patients met the study inclusion criteria, 51.8% of whom were male; the mean (SD) age of patients was 42.8± 13.4 years and follow-up was 2.75±1.45 years. A total of 22.3% (n=131) and 74.5% (n=437) of patients had received ADA and INF, respectively, as index drug. Mean (SD) duration from the initial UC diagnosis to first anti-TNF was 471±476 days. After diagnosis, 89.8% (n=527) of patients received ≥1 new non anti-TNF treatment within 6 months prior to index drug. During the I-phase, 5.3% (n=31) of patients had at least one indicator of inadequate response. Of 338 patients included in the M-phase, 77.8% (n=263) had at least one indicator of inadequate response (Table 1). The overall inadequate response rates did not differ significantly between ADA and INF. Estimated cumulative rates of inadequate response in the M-phase were 66.2% and 77.7% in first and second year, respectively, with a median time to inadequate response of 197 days and no significant difference between the two anti-TNFs. Conclusion: This large-scale real-world assessment of index anti-TNFs for the treatment of UC demonstrated that over three-quarters of patients on maintenance therapy had at least one indicator of inadequate response within two years, with dose escalation being the most commonly observed indicator. Table 1. Indicators of Inadequate Response to Anti-TNFs during the Maintenance Phase Among Patients with Ulcerative Colitis